1. Field of Invention:
The present invention relates to the design and safety of bicycle helmets. In particular this invention relates to the order and layering of materials used in safety helmets.
2. Description of the Prior Art:
Bicycling is an international recreational activity and means of transport that maintains a serious risk of head injury. In addition to bicycling other recreational activities including rollerblading, and skateboarding all maintain a serious risk of head injury. Head injury is a leading cause of accidental death and disability among children in the United States, resulting in over 100,000 hospitalizations every year. Studies have shown that children under the age of 14 are more likely to sustain head injuries than adults, and that children""s head injuries are often more severe than those sustained by adults. In general, head injuries fall into two main categoriesxe2x80x94focal and diffuse. Focal injuries are limited to the area of impact, and include contusions, hematomas, lacerations and fractures. Diffuse brain injuries involve trauma to the neural and vascular elements of the brain at the microscopic level. The effect of such diffuse damage may vary from a completely reversible injury, such as a mild concussion, to prolonged coma and death.
Other activities, such as roller skating, in-line skating and skate boarding are typically conducted on the same types of surfaces as bicycling and can generate speeds similar to bicycling. Therefore, similar patterns of injury and benefits of helmet usage can be expected. Similar design considerations would apply for protective helmets for skating activities, in terms of impact attenuation. One difference between bicycling injuries and skating injuries is that, while 90 percent of bicycle-related head injuries occur on the front of the head, 80 percent of skating-related head injuries occur on the back of the head. Consequently, protective helmets for skating activities may have somewhat different design considerations in terms of coverage and location of protective padding. Protective helmets for aquatic activities, such as windsurfing, kayaking or waterskiing, have similar design considerations in terms of impact attenuation, with the additional requirement for moisture resistance during longterm immersion. Protective helmets for some activities, such as skiing or mountaineering, in addition to impact attenuation, have a need for a broad range of service temperatures.
The use of safety helmets with these various activities has increased; however the incidents of fatalities and injuries have not decreased. An accident, primarily bicycling accidents, result in both linear and rotational injury to be impressed on the brain and can result in contrecoup injuries, intracranial hemorrhages, and concussions. Severe brain damage is caused when the brain is deformed by a non uniform or point of impact pressure to the head. If the pressure to the head is uniform or surrounding the entire brain area, the brain will not be permanently injured. Currently marketed safety helmets are designed and manufactured for direct energy absorption. Current helmets are designed with a hard outer shell (Acrylonitrile-Butadiene-Styrene) and padded layer (expanded polypropylene) for energy absorption from direct, linear impact. The currently available helmets in the market do not provide protection from rotational energy impact or diffuse impact energy to the entire skull area to create uniform skull pressure.
Briefly, the present invention generally relates to protective safety helmets, particularly, this invention provides for a safety helmet designed and manufactured to protect the head and brain from both linear and rotational impact energy. Additionally, this invention is designed and manufactured to diffuse or absorb impact energy in a uniform manner around the head. Additionally, the present invention provides for a design that permits the safety helmet to be constructed of material that allows the safety helmet to be effectively reused after multiple impacts. The present invention is a safety helmet constructed of layers of polyurethane, monoprene gel, polyethylene, and either polycarbonate or polypropylene. The safety helmet manufactured and designed of these materials protects the brain from both linear and rotational impact energy and diffuses or absorbs impact energy in a uniform manner throughout the helmet and over a larger surface of the wearer""s head.